Apparatus for counting sheets while maintaining them in a stack



Apnl 1, 1969 K; SENIOR 3,436,529

" APPARATUS FOR COUNTING SHEETS WHILE MAINTAINING THEM IN A STACK Filed Jan. 24. 1966 Sheet I of 5 K. SENICR 3,436,529 AIPARATUS FOR COUNTING SHEETS WHILE April 1,1969

MAINTAINING THEM IN A STACK Filed Jan. 24. less APPARATUS F COUNTING sn'ms'rs WHILE MAINTAINING THEM IN A STACK I Filed Jam-24, 1966. Sheet 3 A 01 5 Aprll l, 1969 K. NIOR 3,436,529

APPARATUS FOR UNTING SHEETS WHILE MAINTAINING THEM IN A STACK Filed Jan. 24, 1966 Sheet 4 of 5 Filed Jan. 24, 1966 Sheet 5 April 1, 1969 K. SENIOR 3,436,529

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RAISE LOCK United States Patent G 3,436,529 APPARATUS FOR COUNTING SHEETS WHILE MAINTAINING THEM IN A STACK Kenneth Senior, Frinton-on-Sea, England, assignor t Vacunmatic Limited, Harwich, England, a British company Filed Jan. 24, 1966, Ser. No. 522,672 Claims priority, application Great Britain, Jan. 25, 1965, 3,224/65 Int. 'Cl. G06c 29/00 US. Cl. 235-92 12 Claims This invention relates to apparatus for counting sheets while maintaining them in a stack, and of the kind comprising a rotary element having a slotted peripheral portion which may project between parts of adjacent sheets in the stack, suction means associated with the rotary element and arranged to displace a part of a sheet to a position where it may pass through the slot from one side of the peripheral portion to the other as the rotary element rotates, and means for counting each displacement of a part of a sheet.

Heretofore, in apparatus of this kind, the axis of rotation of the rotary element has been parallel with the length of the stack of sheets, with the result that the rotary element and associated apparatus (for example a carrier for the element) have been disposed opposite the gap in the stack formed by the peripheral portion of the rotary element. The result of this is that there is little space in the vicinity of the gap in which to place other devices which must be in that locality, such as devices for inserting tabs between sheets in the stack at predetermined intervals. An object of the invention is to overcome this difficulty.

According to the invention a sheet counting apparatus of the kind referred to is characterised in that the axis of rotation of the rotary element is inclined to, or is at right angles to, the length of the stack and the slotted peripheral portion is so shaped that it may project between parts of adjacent sheets in the stack and operate in a similar manner as heretofore.

In one form of the invention the rotary element may be dish-shaped or saucer shaped, for example the peripheral portion of the rotary element may comprise a peripheral flange extending out of the general plane of the other part of the rotary element at such an angle that at least a part of the outer surface of the flange may sweep over and in contact with a surface of a sheet in the stack.

In the case where the axis of the rotary element is inclined to the general planes of the sheets the outer surface of the peripheral flange is preferably part conical.

In any of the above arrangements the suction means may comprise at least one suction port adjacent the leading edge of the slot, on the outer face of the peripheral portion, the suction port communicating with a source of suction through valve means so controlled by the rotation of the rotary element that the port is subtracted to suction as it passes above the surface of a part of a sheet.

In one such arrangement the suction port communicates with an opening in a surface of the rotary element, which opening is arranged to sweep past a stationary port, connected to a source of suction, as the rotary element rotates.

The following is a more detailed description of one form of the invention reference being made to the accompanying diagrammatic drawings in which:

FIGURE 1 is a part vertical section part side elevation of a slotted counter rotor;

FIGURE 2 is a view looking from the right of FIG- URE 1 and showing diagrammatically the mounting for the counter rotor;

FIGURE 3 is a perspective view showing the attitude of the counter rotor in relation to a stack of sheets;

FIGURE 4 is a side view of part of the counter rotor showing the configuration of one of the slots;

FIGURES 5 to 7 are sections through one of the slots in the counter rotor showing diagrammatically the manner in which a part of a sheet in the stack is operated on by the rotor; and

FIGURE 8 is a block diagram of the counter control circuit.

The counter rotor 10 comprises a circular disc 11 integrally formed with a peripheral flange 12 extending out of the general plane of the disc 11. The outer surface of the flange 12- is frusto-conical and the rotor is arranged to rotate about an axis 17 so inclined to the general planes of the sheets in a stack 13- that the lowermost portion of the outer surface of the flange 12 is horizontal, so that a part of that surface may sweep over the upper surface of a corner of each sheet in the stack. The rotor 10 is mounted on a shaft (not shown) which is rotatably mounted in bearings (also not shown) in a carriage 14. A pulley wheel 15, axially spaced from the rotor 10, is secured to the shaft carrying the rotor 10 and is encircled by an endless belt 16 which also encircles a further pulley wheel 18 secured to a further shaft 19 rotatable in bearings on the carriage 14. The shaft 19 is driven by an electric motor (not shown) also mounted on the carriage 14.

At opposite sides of the carriage 14 there are rotatably mounted rollers 20 which engage vertical pillars 21, mounted on a base (not shown), so that the carriage 14 and rotor '10' are movable in an up and down direction between the pillars 21. The weight of the carriage and roller assembly is counterbalanced by weights 22 at the ends of cords 23 which pass over pulley wheels 24 mounted at the upper ends of the pillars 21, the other ends of the cords 23 being secured to opposite sides of the carriage 14. An air operated ram indicated diagrammatically at 25 is connected between the carriage 14 and a fixed support (not shown) for the counter for the purpose of moving the carriage and counter assembly upwardly or downwardly.

Referring now to FIGURES 3, 4 and 5: the peripheral flange of the rotor 10 is formed with twelve slots 26 each of which passes in an inclined manner through the flange. The rotor is arranged to rotate in the direction of the arrows shown in the figures and the outer surface of the flange on the leading side of each slot 26 is formed with a shallow recess 27 in which are formed three suction ports 28. A peripheral groove 27a is formed around the outer surface of the flange 12 to permit the passage of light across the sheet corner as described below.

As best seen in FIGURE 1 each suction port 28 communicates with an opening 29 in the surface of the disc 11 on the opposite side of the disc to the flange 12. Opposite the path of movement of the openings29, around the axis of rotation of the rotor, is a nylon block 30 formed .with a central bore 31 which leads to a conduit 32 which is connected to a vacuum pump (not shown). The nylon block 30 is urged by a compression spring 33 into contact with the surface of the disc 11 so that the surface of the disc sweeps over the end face of the nylon block as the disc rotates. It will thus be appreciated that each time an opening 29 comes into register with the end of the bore 31 in the nylon block 30, as the rotor rotates, its corresponding suction port 28 will be placed in communication with the vacuum pump.

As each slot 26 sweeps over the corner of a sheet in the stack the actions shown in FIGURES 5, 6 and 7 take place. When the slot 26 reaches the position shown in FIGURE 5 the leading port 28 is placed in communication with the vacuum pump so that the corner of the sheet 34 over which the outer surface of the flange 12 is sweeping is sucked into the recess 27 on the leading edge of the slot. As the rotor continues to rotate the other ports 28 are successively placed in communication with the vacuum pump so that the corner of the sheet 34 is retained in the recess 27 until the trailing edge 35 of the slot passes beneath the corner of the sheet which has been sucked up, thus causing the corner of the sheet to pass through the slot 26 from the lower to the upper side of the flange 12 as shown in FIGURE 7.

The rotor is caused to bear down on the sheet beneath the flange 12 due to its weight which is partly borne by the aforesaid counterbalancing weights 22. Thus due to its weight the rotor and carriage 14 will move downwardly as the corners of the sheets in the stack are successively transferred through the slots 26 from one side of the flange 12 to the other. It will be appreciated that since there are provided twelve slots 26 the corners of twelve sheets will be transferred from the lower to the upper side of the flange 12 during each rotation of the rotor.

A clamping device indicated diagrammatically at 36 in FIGURE 3 is provided to hold the stack of sheets in position on the base while being operated upon by the counter rotor. The clamp comprises a circular rubber pad 37 mounted on one end of the piston rod 38 of a vertically disposed air operated ram 39. Thus when the ram 39 is extended the stack of sheets 13 is clamped between the rubber pad 37 and the base on which the stack is resting.

In place of the single rubber pad a number of smaller spring loaded pads or pins may be used to distribute the clamping pressure. This is particularly desirable when the surface of the stack is not flat.

Various means may be employed for counting each displacement of the corner of a sheet so as to record the number of sheets in the stack 13. In one counting arrangement a photoelectric cell unit 40 is mounted on the carriage 14 so as to move u and down with the carriage in fixed relation to the rotor 10. The photoelectric cell unit is disposed on one side of a corner of the stack of sheets and a light source 41 also mounted on the carriage 14 is disposed on the other side of the corner.

Preferably the light source 41 is of a kind emitting infrared light and the photocell unit 40 is of a kind adapted to respond to infrared light. The beam of light from the light source 41 shines through the groove 27A and across the gap created by the flange 12 between two adjacent sheets in the stack. With this arrangement the beam of light passing through the gap and falling on the photoelectric cell is obscured each time a corner of a sheet passes from the lower side of the flange 12 to the upper side and this may be arranged, in known manner to send an electric pulse to an electronic counting device.

The manner in which the various controls of the counter are interconnected and are operated will now be described with reference to the block diagram shown in FIGURE 8. Pulses from the photocell unit 40, caused by the beam from the emitter 41 being interrupted by the corners of sheets, are fed into an input unit 42 which comprises a Schmitt trigger. Output signals from the Schmitt trigger are fed to the Input Fault unit 42, which is a time delay unit which is not operated as long as signals continue to be received from the input unit. Should however input signals fail to arrive, due to a fault, then the Input Fault unit 42 sends a signal to a Fault Gate 44 which operates a control 45 for the motor driving the rotor 10, so as to stop the motor, and also operates a control 46 to actuate an air control air valve which stops the vacuum supply to the parts 28.

The counter 46 incorporates a conventional digital counter to indicate the number of pulses received from the photo-electric cell unit 40. Where the counter is used to check the number of sheets in standard stacks of 75 sheets, the counter may be pre-set to indicate a number of sheets which should be in each stack. During operation of the apparatus, the counter is arranged to compare the number of pulses received with the number pre-set on the counter. If the number of pulses received agrees with the pre-set number, Output 2 (indicated at 47) will send a signal to a Correct Gate 48, which in turn sends signals to the control for the counter motor and the control 46 for the vacuum supply. The Correct Gate 48 also sends a signal to a control 49 for the clamp 36, raising the clamp so that the stack of sheets can be removed from the machine.

Should however the number of pulses received from the photoelectric cell unit 40 not agree with the number to which the counter has been pre-set, Output 1 (indicated at 50) sends a signal to the Fault Gate 44 which stops the counter motor and vacuum supply through the controls 45 and 46 respectively, but does not send a signal to the control 49 for the clamp 36. The clamp is not therefore raised to release the stack of sheets. This draws the attention of the operator of the machine to the fact that the number of sheets in the stack is incorrect. The stack of sheets may be removed from the machine by manual release of the clamp by operation of a Manual Gate Release 51.

A Raise Control, indicated at 52, controls the air operated ram 25 and is arranged when actuated to operate the ram 25 to raise the carriage 14 carrying the counter rotor. The Raise Lock comprises a microswitch fitted to guide panels on the base supporting the stack of sheets, and this microswitch is so arranged as to be held in circuit by the stack of sheets pressing against the guides. The arrangement is such that when the microswitch is operated by the presence of a stack of sheets in the counting position, the Raise Control 52 cannot be operated to raise the counter rotor. However when a signal is sent from Output 2, indicating that a correct count has been reached, the clamp 36 is raised, as mentioned earlier, and thus the stack of sheets can be removed from the counter whereupon the Raise Control 52 is actuated to raise the carriage 14. At the same time as the Raise Control 52 is operated, it also automatically sends a signal to a Reset device 54 which resets the digital display to zero. There is also provided a manual control for resetting the digital display to zero. The controls for the vacuum supply, the motor for rotating the rotor 10, the clamp 36 and the rotor raising ram 25 can also be operated manually if required.

Thus the operation of the counter is as follows: with the rotor 10 and clamp 36 in their uppermost positions the operator presets on the Counter 46 the number of sheets which there should be in each stack to 'be counted by the machine, and then places a stack of sheets against guides beneath the rotor 10. The manual controls for the ram 25 and clamp 36 are then operated to clamp the stack of sheets in position and to bring the rotor down so that the outer surface of the flange 12 rests across the corner of the uppermost sheet in the stack. The apparatus is then switched on and the rotor rotates transferring the corners of the sheets from the lower to the upper side of the rotor as referred to earlier, the rotor moving downwardly under its own weight. When the rotor reaches the bottom of the stack of sheets, if the number of sheets counted corresponds to the number preset on the counter, the clamp 36 moves upwardly to release the stack, the stack may be Withdrawn from the machine by the operator, and the rotor is automatically returned to its uppermost position by the ram 25.

Should however the number of sheets counted differ from the number preset on the counter, a signal is sent from Output 1. The vacuum supply to the ports 28 is cut ofl. and the motor driving the rotor is stopped, but the clamp 36 is not raised and thus the operator realises that the stack contains an incorrect number of sheets. The operator can then remove the incorrect stack of sheets from the counter by manual operation of the control for raising the clamp 36.

The arrangement according to the invention, in which the axis of rotation of the rotor is inclined to the general plane of the sheets, has the advantage that the bulk of the supporting means for the rotor and associated equipment is disposed above and away from the gap created by the flange 12 in the stack so that there is ample room beneath the rotor and the carriage, if required, for a known form of tape inserting device which may be arranged to insert a short length of tape automatically in the gap created by the flange 12 at predetermined intervals. With various other earlier arrangements the support means for the counter have had to be disposed opposite, above, and below the gap in the corner of the stack of sheets which thus leaves little room for mechanisms, such as a tape inserting mechanism, which require to be located near to the gap in the stack of sheets.

Although the described arrangement of the counter is preferred, in an alternative arrangement a counter is arranged to operate once during each rotation of the rotor. This can be done in known manner by means of a photocell or magnetic or mechanical device and in each case means are provided for gating the signal derived from this source so as to inhibit the operation of the counter if a part of a sheet fails to be deflected by the rotor.

This means may comprise a port which is positioned on the inner side of the flange 12 and is placed in communication with the vacuum pump immediately after the ports 28 have closed. If the corner of the sheet passes through the slot 26 then this corner will cover the port on the inner side of the flange 12 and thus maintain a steady vacuum which will allow the signal derived from the rotation of the rotor to be passed to the counting device and thus the passage of the sheet will be recorded. If on the other hand, the corner of a sheet has not passed through the slot, the port on the inner side of the flange would be in communication with atmosphere, and this may be arranged in a known manner to inhibit the signals obtained by means of the revolution of the rotor.

In a further alternative arrangement (not shown) the photoelectric assembly 40, 41 is replaced by two curved light transmitting tubes of the known kind comprising bunched glass fibres. The light tubes are arranged to be stationary within a circumferential recess on the inner surface of the flange 12 and have their lower ends disposed on opposite sides of the corner of stack 13 and their upper ends disposed respectively adjacent a light source and a photoelectric cell. With this arrangement the light source and photoelectric cell may be brought well clear of the gap in the corner of the stack created by the flange 12.

Although in the arrangement shown there are provided twelve slots in the flange of the rotor it will be appreciated that any number of similar slots and suction ports may be spaced apart around the periphery of the flange in order to vary the speed of counting of the device for a given rotational speed, or conversely to enable the rotor 10 to be rotated at a faster or slower speed for a given rate of counting.

As mentioned earlier the rotor 10 may be arranged to rotate about an axis which is parallel to the general planes of the sheets and in this case the outer surface of the flange 12 is cylindrical. It will be appreciated that with this arrangement the depth of stack which can be counted is limited by the inner diameter of the rotor 10.

If required the whole assembly of the rotor 10 and carriage 14 may be inverted and suitable means provided for traversing the head upwardly with respect to the corner of the stack of sheets. Alternatively the rotor 10 may be arranged to rotate about a stationary axis and the stack of sheets 13 traversed past the rotor.

In any of the described arrangements the general planes of the sheets in the stack need not necessarily be arranged to be horizontal but may be arranged in any suitable attitude.

I claim:

1. A sheet counting apparatus comprising: a support for a stack of sheets, a rotary element having its axis of rotation inclined to the length of the stack, which rotary element has a peripheral portion shaped to project between parts of adjacent sheets in the stack to separate them, which peripheral portion is formed with at least one slot through the thickness thereof and extending inwardly away from its outer edge, suction means associated with the rotary element for displacing a part of a sheet to a position where it passes through the slot from one side of the peripheral portion to the other as the rotary element rotates, means for effecting relative movement between the rotary element and the stack along the length thereof, lwhereby parts of the sheets in the stack are successively transferred from one side of the peripheral portion of the rotor to the other, and means for counting each displacement of a part of a sheet.

2. A sheet counting apparatus according to claim 1 wherein the rotary element is dish shaped.

3. A sheet counting apparatus according to claim 2 wherein the peripheral portion of the rotary element comprises a peripheral flange extending out of the general plane of the other part of the rotary element at such an angle that at least a part of the outer surface of the flange may sweep over, and in ontact with, a surface of a sheet in the stack.

4. A sheet counting apparatus according to claim 3 wherein the axis of the rotary element is inclined to the general planes of the sheets and the outer surface of the peripheral flange is part conical.

5. A sheet counting apparatus according to claim 1 wherein said suction means comprise at least one suction port adjacent the leading edge of the slot, on the outer face of the peripheral portion, the suction port communicating with a source of suction through valve means so controlled by the rotation of the rotary element that the port is subjected to suction as it passes above the surface of a part of a sheet.

6. A sheet counting apparatus according to claim 5 wherein the suction port communicates with an opening in the surfaces of the rotary element, which opening is arranged to sweep past a stationary port, connected to a source of suction, as the rotary element rotates.

7. A sheet counting apparatus according to claim 1 wherein the stack is arranged to be stationary and means are provided for traversing the rotary element in the direction of the length of the stack as the rotary element rotates.

8. A sheet counting apparatus according to claim 7 wherein the rotary element is freely movable in the direction of the length of the stack, the attitude of the stack and rotary element being such that, as the element rotates, it traverses along the stack under its own weight.

9. Apparatus according to claim 7 wherein movement of the rotary element in the direction of the length of the stack may be effected by a fluid energised ram.

10. A sheet counting apparatus according to claim 1 wherein releasable clamping means are provided for maintaining a stack of sheets in position on the apparatus.

11. A sheet counting apparatus according to claim 10 wherein there is provided a counter adapted to count the sheets operated upon by the rotary element and to effect automatic release of the clamping means only when the count agrees with a predetermined value.

12. A sheet counting apparatus according to claim 10 wherein there is provided a support member to receive a stack of sheets to be operated on by the rotary element, and the clamping means comprise a fluid energised ram carrying a clamping member which, when the ram is extended, is urged downwardly against the uppermost sheet in the stacks and clamps the stack between the clamping element and the support member.

(References on following page) References Cited UNITED STATES PATENTS GREGORY J. MAIER, Assistant Examiner.

Holmen 27127 s. CL Richardson 27127 Buchholz. 5 271-47 Hayes.

MAYNARD R. WILBUR, Primary Examiner. 

1. A SHEET COUNTING APPARATUS COMPRISING: A SUPPORT FOR A STACK OF SHEETS, A ROTARY ELEMENT HAVING ITS AXIS OF ROTATION INCLINED TO THE LENGTH OF THE STACK, WHICH ROTARY ELEMENT HAS A PERIPHERAL PORTION SHAPED TO PROJECT BETWEEN PARTS OF ADJACENT SHEETS IN THE STACK TO SEPARATE THEM, WHICH PERIPHERAL PORTION IS FORMED WITH AT LEAST ONE SLOT THROUGH THE THICKNESS THEREOF AND EXTENDING INWARDLY AWAY FROM ITS OUTER EDGE, SUCTION MEANS ASSOCIATED WITH THE ROTARY ELEMENT FOR DISPLACING A PART OF A SHEET TO A POSITION WHERE IS PASSES THROUGH THE SLOT FROM ONE SIDE OF THE PERIPHERAL PORTION TO THE OTHER AS THE ROTARY ELEMENT ROTATES, MEANS FOR EFFECTING RELATIVE MOVEMENT BETWEEN THE ROTARY ELEMENT AND THE STACK ALONG THE LENGTH THEREOF, WHEREBY PARTS OF THE SHEETS IN THE STACK ARE SUCCESSIVELY TRANSFERRED FROM ONE SIDE OF THE PERIPH- 